Amphibious marsh craft

ABSTRACT

A tracked, amphibious vehicle, comprising at least two, spaced, elongated pontoons disposed generally parallel to one another. A platform structure can be supported by and structurally connects the pontoons, the platform structure including a transom, a lowermost generally horizontally extending panel above a free clearance area under a bottom panel and between the pontoons through which terrain and debris can pass. A hydraulic drive system can propel the vehicle, said drive system including left and right hydraulic motors mounted on the pontoons. At least one series of longitudinally spaced bogie wheels for supporting said vehicle can be mounted along the bottom of the pontoons. A continuous, endless belt can encircle each pontoon and engages the bogie wheels. Ground-engaging cleats assembled on the outer surface of each belt and covering the pontoon bottom provide traction to the vehicle. Gearing interfaces the motor with the endless belts. A supplemental, marine drive assembly includes: a hydraulic motor having a rotary device, shaft, with an axis, a propeller shaft having an axis wherein the motor axis and propeller axis are aligned, a universal joint connecting the hydraulic motor to the transom, and a housing including a sleeve that contains the propeller shaft, a first vertical plate connected to the sleeve and a second vertical plate connected to the sleeve below the first plate.

CROSS-REFERENCE TO RELATED APPLICATIONS

This is a continuation of U.S. patent application Ser. No. 15/494,928,filed 24 Apr. 2017 (issued as U.S. Pat. No. 9,931,899 on 3 Apr. 2018),which is a continuation of U.S. patent application Ser. No. 14/859,822,filed 21 Sep. 2015 (issued as U.S. Pat. No. 9,630,465 on 25 Apr. 2017),which claims benefit of U.S. Provisional Patent Application Ser. No.62/052,543, filed 19 Sep. 2014, which is hereby incorporated herein byreference.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not applicable

REFERENCE TO A “MICROFICHE APPENDIX”

Not applicable

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to amphibious tracked craft having a frameconnecting two spaced apart pontoons, a transom and an improvedsupplemental drive system that employs a hydraulically driven propeller,a universal joint connection to the transom, a hydraulic motor with inline drive and improved tilt and steerage.

2. General Background of the Invention

Amphibious marsh craft can be seen in the following US patents issued toJohn B. Coast, each of which is hereby incorporated herein by reference:U.S. Pat. Nos. 4,433,634; 4,961,395; 5,899,164; 6,234,260 and 6,305,882.In the past, such amphibious craft propel themselves across streams,lakes or other water bodies by simply running their tracks. Such crafthave limited swimming capability using the tracks to propel in thewater. Lightly loaded machines that float high in the water (e.g., withthe centerline of the rear drive sprockets above the waterline) arecapable of “swimming” at low speeds (e.g., approximately 2 mph). Thiscapability allows these amphibious machines to cross canals, rivers,creeks, bayous, lakes, bays, etc., provided that wind and currents arelow. One of the utilities of such amphibious craft is to carry heavyequipment such as seismic equipment or auger installing equipment. Whenthe load on the machines increases, the rear of the machine and the rearsprocket centerline can dip below the waterline. The swimming capabilitywith tracks only propelling then decreases to near zero.

In the prior art, some amphibious craft have provided a transom on therear designed to accept an outboard motor. Outboards up to 40 horsepower(hp) have been used to propel these amphibious machines at speeds ofover 3 mph. Outboard motors have thus given such machines goodpropulsion and maneuverability. However, this capability is rarely usedbecause operators typically do not want to bother with handling theoutboard motors and/or the gasoline tanks or fuel tanks required.Outboard motors are typically heavy four stroke units weighing twohundred pounds ore more (e.g., 40 horsepower Honda outboard weighs 214pounds).

BRIEF SUMMARY OF THE INVENTION

The present invention provides an in line hydraulic drive unit ofimproved configuration which can easily be attached to the rear of anamphibious marsh craft as needed and be removed very easily if not inuse.

Various embodiments preferably provide a tracked, amphibious vehicle,comprising at least two, spaced, elongated pontoons disposed generallyparallel to one another. A platform structure is preferably supported byand may structurally connect the pontoons, the platform structurepreferably including a transom, a lowermost generally horizontallyextending panel above a free clearance area under a bottom panel andbetween the pontoons through which terrain and debris can pass. Ahydraulic drive system may propel the vehicle, said drive systemincluding left and right hydraulic motors mounted on the pontoons, theleft motor mounted on a left pontoon, the right motor mounted on a rightpontoon. At least one series of longitudinally spaced bogie wheels arepreferably provided for supporting said vehicle mounted along the bottomof each of said pontoons. A continuous, endless belt preferablyencircles each pontoon and engages the bogie wheels and ground-engagingcleats assembled on the outer surface of each belt and preferablycovering the pontoon bottom for providing traction to the vehicle.

In various embodiments, each of the hydraulic motors can have gearingthat interfaces the motor with the endless belts.

In various embodiments, a supplemental, marine drive assembly can beprovided that includes:

-   -   a hydraulic motor having a rotary device, shaft, with an axis;    -   a propeller shaft having an axis;    -   wherein the motor axis and propeller axis are preferably        aligned;    -   a universal joint that preferably connects the hydraulic motor        to the transom;    -   wherein the universal joint preferably includes an attachment        that is on the transom and above the said horizontally extending        panel;    -   a housing preferably including a sleeve that contains the        propeller shaft, a first plate preferably connected to the        sleeve and a second plate preferably connected to the sleeve        below the first plate.

In various embodiments, the first and second plates can be vertical.

In various embodiments, the first and second plates preferably define aplane.

In various embodiments, the propeller can be movable between a lowerposition below said horizontally extending panel and an upper positionabove said horizontally extending panel.

In various embodiments, said sleeve can be movable between a lowerposition below said horizontally extending panel and an upper positionabove said horizontally extending panel.

In various embodiments, a horizontal plate can be attached to said firstplate.

In various embodiments, a cavitation plate can be attached to the firstplate and the horizontal plate.

In various embodiments, an arm is preferably connected to the housing atthe horizontal plate.

In various embodiments, an arm are preferably connected to the housingat the horizontal plate and the arm attaches to the horizontal plate ata first position and to the housing at a second position that is behindthe first position.

In various embodiments, an actuator can be provided that lifts andlowers the propeller and sleeve.

In various embodiments, an actuator can be provided that pivots thesleeve and propeller between port and starboard positions.

In various embodiments, the first and second plates preferably define aplane.

In various embodiments, the propeller can movable between a lowerposition and an upper position above the lower position panel.

In various embodiments, the invention can further comprise a horizontalplate attached to the first plate.

In various embodiments, the invention can further comprise a cavitationplate attached to the first plate and the horizontal plate.

In various embodiments, the arm can attach to the horizontal plate at afirst position and to the housing at a second position that is behindthe first position.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

For a further understanding of the nature, objects, and advantages ofthe present invention, reference should be had to the following detaileddescription, read in conjunction with the following drawings, whereinlike reference numerals denote like elements and wherein:

FIG. 1 is a perspective view of a preferred embodiment of the apparatusof the present invention;

FIG. 2 is a partial perspective exploded view of a preferred embodimentof the apparatus of the present invention;

FIG. 3 is a partial perspective view of a preferred embodiment of theapparatus of the present invention;

FIG. 4 is a partial perspective exploded view of a preferred embodimentof the apparatus of the present invention;

FIG. 5 is a partial elevation end view of a preferred embodiment of theapparatus of the present invention;

FIG. 6 is a sectional view taken along lines 6-6 of FIG. 5;

FIG. 7 is a detailed view of a preferred embodiment of the apparatus ofthe present invention taken from detail 7 of FIG. 6;

FIG. 8 is a fragmentary detail view of a preferred embodiment of theapparatus of the present invention taken from detail 8 of FIG. 6;

FIG. 9 is a schematic side elevation view of a preferred embodiment ofthe apparatus of the present invention illustrating the propeller in theuppermost position;

FIG. 10 is a schematic side elevation view of a preferred embodiment ofthe apparatus of the present invention illustrating the propeller in thelowermost position;

FIG. 11 is a schematic elevation end view of a preferred embodiment ofthe apparatus of the present invention illustrating the propeller in adown-left position;

FIG. 12 is a schematic elevation end view of a preferred embodiment ofthe apparatus of the present invention illustrating the propeller in adown-center position;

FIG. 13 is a schematic elevation end view of a preferred embodiment ofthe apparatus of the present invention illustrating the propeller in adown-right position;

FIG. 14 is a perspective view of an alternate embodiment of theapparatus of the present invention;

FIG. 15 is a perspective view of a preferred embodiment of the apparatusof the present invention;

FIG. 16 is a partial perspective view of a preferred embodiment of theapparatus of the present invention;

FIG. 17 is a partial perspective view of a preferred embodiment of theapparatus of the present invention;

FIG. 18 is partial perspective view of an alternate embodiment of theapparatus of the present invention; and

FIG. 19 is a partial perspective exploded view of an alternateembodiment of the apparatus of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

FIGS. 1-13 and 15-17 show a preferred embodiment of the apparatus of thepresent invention designated generally by the numeral 50 in FIGS. 1 and15. Amphibious tractor vehicle 50 provides a frame/platform structure 51that is preferably connected to a pair of spaced apart pontoons 52, 53.The pontoons include port side pontoon 52 and starboard side pontoon 53(see FIGS. 1, 15-17). Each pontoon preferably carries a plurality ofbogie wheels 54. Endless tracks or tracks 55 preferably encircle eachpontoon and engage the bogie wheels 54. The tracks 55 carry a pluralityof cleats 56. The port side pontoon 52 preferably has port hydraulicmotor drive 57. The starboard pontoon 53 preferably has starboardhydraulic motor drive 58. Each motor drive 57, 58 can be a direct drivemotor that connects to the endless tracks 55 (e.g., via a drive shaft)for driving it around pontoon 52 or 53. In general, tracked amphibiousvehicles having port and starboard pontoons tracks and hydraulic drivemotors are known, as seen for example in U.S. Pat. Nos.: 4,433,634;4,961,395; 5,899,164; 6,234,260; and 6,305,882, each said patent herebyincorporated herein by reference.

In FIG. 1, amphibious track vehicle 50 preferably provides a cabin orcontrol station 59 and a hydraulic power unit 60. Hydraulic power unit60 can include an engine such as a diesel engine and one or morehydraulic pumps.

A drive assembly DA is seen in FIGS. 1-13. The drive assembly DA can beseen in more detail in FIGS. 2-13. In FIGS. 9 and 10, the frame/platformstructure 51 of amphibious tractor vehicle 50 preferably includes anunderside or bottom panel 40 with a horizontal surface which is thelowest part of the frame/platform structure 51 in between the pontoons52, 53. in FIGS. 9 and 10, reference line 43 is an extension of thehorizontal surface of bottom panel 40 of frame/platform structure 51.Notice in FIG. 10 that propeller 16 is positioned below reference line43 and bottom panel 40 in a driving position. FIG. 9 illustrates anelevated position of propeller 16 wherein it is above reference line 43and bottom panel 40.

Drive assembly DA preferably attaches to transom 41 above reference line43 as seen in FIGS. 9 and 10. It should be understood that theattachment of drive assembly DA to transom 41 can be by universal joint42 which is preferably below each of the hydraulic motor drives 57, 58(see FIGS. 1, 9-10, 16-17). The attachment at universal joint 42 ispreferably above bottom panel 40 and reference line 43, not subjected todebris or obstructions such as logs or stumps that might travel inbetween pontoons 52, 53 and below bottom panel 40. Arrows 49 illustratemovement of drive assembly DA propeller 16 between upper (FIG. 9) andlower (FIG. 10) positions.

Drive assembly DA in FIGS. 2, 5-8 preferably includes a sleeve 34 thathouses prop drive shaft 11. Prop drive shaft 11 connects to hydraulicmotor 4 with splined bushing 6, as seen in FIG. 7. Other components thatinterface motor 4 to shaft 11 are motor mount 35 with interior or cavity36, hex bolts 1, lock washers 2, flat washers 3, O-ring 5, snap ring 7,nut 8, lock washer 9 and ball bearing 10. Prop drive shaft 11 alsoconnects to propeller 16, as seen in FIG. 8. Prop drive shaft 11occupies sleeve 34 and extends to propeller 16 forming a connectiontherewith. Prop drive housing weldment 12 (which can include upper skeg33 and lower skeg 66) is also shown in FIGS. 6-8. The skegs 33,66interface with sleeve 34 and motor mount 35. The weldment or assembly 12(see FIG. 2) of sleeve 34, skegs 33,66, horizontal plate 32, plate 20and motor mount 35 can be of welded steel or welded aluminumconstruction or it can be a casting. Other components that form theconnection between shaft 11 and propeller 16 include plain bearing 13,shaft seal 14, nuts 15 and nut 17 (see FIG. 8).

In FIGS. 2-13, drive assembly DA can provide arm 18 and strut 19. Arm 18preferably connects to cavitation plate 20. Strut 19 preferably connectsto plate 32 which can be welded to vertical plate or weldment 33. FIGS.3-4 and 9-13 illustrate in more detail the universal joint or attachment42 that preferably connects between plate 33 at opening 61 and transom41. Pivot mount plate 21 attaches to transom 41. Prop drive pivotchannel 24 attaches to plate 21. Bolted connections including hex bolt27, lock washers 26 and flat washers 25 can be used to affix pivotchannel 24 to plate 21. Prop drive pivot pin 22 forms a connectionbetween prop drive pivot channel 24 and pivot block 28, through openings62 of pivot channel 24 and opening 65 of pivot block 28. A boltedconnection can be used to bolt pivot block 28 to plate 33. In FIG. 4,that bolted connection includes hex bolt 31, flat washers 30 and nut 29.A pin (e.g., hairpin) can be provided at 23 for retaining pivot pin 22in openings 62 of channel 24. Openings 63 and pivot block 28 arereceptive of the bolted connection that includes bolt 31, washers 30 andnut 29. A slot 64 in pivot block 28 is receptive of plate 33. Duringassembly, the openings 61, 63 are aligned when plate 33 is placed intoslot 64.

In FIGS. 11-13, control valve 37 can be mounted on arm 18. The controlvalve 37 can include an actuator 38 that can be moved between forwardand backward positions as well as a neutral position. In FIG. 3, driveassembly DA provides one or more hydraulic hoses 39 that interfacebetween motor 4 and control valve 37. Hoses 39 also form an interfacewith the hydraulic power unit 60.

FIG. 14 shows an alternate embodiment that employs actuators 44, 45. Theactuator 44 can be an electric actuator to control left or rightsteerage. The actuator 45 can be an electric actuator to raise and lowerdrive assembly DA and propeller 16. Support 46 can be provided,extending upwardly from pivot block 28. Attachment 47 on plate 32preferably provides an attachment for one end portion of actuator 45.The other end of actuator 45 preferably attaches to support 46.Similarly, the actuator 44 preferably affixes to transom 41 atattachment 48 and to pivot block 28 at its opposing end portion atattachment 67.

FIGS. 18 and 19 show an alternate embodiment that employs prop driveweldment/ring 70. Weldment/ring 70 can be connected to prop drivehousing weldment 88. Prop drive housing weldment 88 (which can includeupper skeg 87 and lower skeg 89) is shown in FIGS. 18, 19. The skegs 87,89 interface with sleeve 34 and motor mount 35. The weldment or assembly88 of sleeve 34, skegs 87, 89, horizontal plate 90 and motor mount 35can be of welded steel or welded aluminum construction or it can be acasting.

Prop drive weldment/ring 70 connects to prop drive housing weldment 88at upper skeg 87 and lower skeg 89. The weldment or assembly of skegs87, 89 and prop drive weldment/ring 70 can be of welded steel or weldedaluminum construction or it can be a casting. Alternatively, componentsthat form the connection between shaft 11 and propeller 16, includingplain bearing 13, shaft seal 14, nuts 15 and nut 17 (see FIG. 19), canbe used to secure or hold prop drive weldment/ring 70 to prop drivehousing weldment 88.

FIG. 19 illustrates in more detail an alternate universal joint orattachment 42 that preferably connects between plate 87 at opening 61and transom 41. Mounting plate 79 attaches to transom 41 by forming aconnection with plate 84. Nuts 81, lock washers 82, and flat washers 83attach to eyebolts 73 to connect plate 84, transom 41, and plate 79together.

Prop drive mounting channel 72 attaches to plate 79. Bolted connectionsincluding bolts 80 can be used to affix mounting channel 72 to plate 79.Prop drive pivot pin 22 forms a connection between prop drive mountingchannel 72 and pivot block/swivel link 28, through openings 85 ofmounting channel 72 and opening 65 of pivot block/swivel link 28. Abolted connection can be used to bolt pivot block 28 to plate 87. InFIG. 19, that bolted connection includes hex bolt 31, flat washers 30and nut 29. A pin (e.g., hairpin) or pivot pin clip can be provided at23 for retaining pivot pin 22 in openings 85 of channel 72. Duringassembly, the openings 61, 63 are aligned when plate 87 is placed intoslot 64.

In FIGS. 18 and 19, prop drive control valve 78 can be mounted on arm 18using bolts 75, lock washer 76, and flat washers 77. The control valve78 can include an actuator 86 that can be moved between forward andbackward positions as well as a neutral position. In FIG. 18, driveassembly DA provides one or more hydraulic hoses 39 that interfacebetween motor 4 and control valve 78. Hoses 39 also form an interfacewith the hydraulic power unit 60.

Drive assembly DA can include a prop drive name tag 71 secured to propdrive housing weldment 88.

The following is a list of parts and materials suitable for use in thepresent invention:

PARTS LIST

PART NUMBER DESCRIPTION DA drive assembly  1 hex bolt  2 lock washer  3flat washer  4 motor  5 O-ring  6 splined bushing  7 snap ring  8 nut  9lock washer 10 ball bearing 11 prop drive shaft 12 prop drive housingweldment/assembly 13 plain bearing 14 shaft seal 15 nut 16 propeller 17nut 18 arm 19 strut 20 plate/cavitation plate 21 pivot mount plate 22prop drive pivot pin 23 hairpin for pivot pin/clip 24 prop drive pivotchannel 25 flat washer 26 lock washer 27 hex bolt 28 pivot block/swivellink 29 nut 30 washer 31 hex bolt 32 horizontal plate 33 verticalplate/skeg/weldment 34 sleeve 35 motor mount 36 cavity 37 control valve38 actuator 39 hose 40 bottom panel/horizontal surface/underside 41transom 42 universal joint/attachment 43 reference line 44 actuator 45actuator 46 support 47 attachment 48 attachment 49 arrow 50 amphibioustracked vehicle 51 frame/platform structure 52 pontoon, port 53 pontoon,starboard 54 bogie wheel 55 track/endless track 56 cleat 57 porthydraulic motor drive 58 starboard motor drive 59 cabin/control station60 hydraulic power unit 61 opening 62 opening 63 opening 64 slot 65opening 66 vertical plate/skeg 67 attachment 70 prop driveweldment/cover 71 prop drive name tag 72 prop drive mounting channel 73eyebolt 74 shackle 75 bolt 76 lock washer 77 flat washer 78 prop drivecontrol valve 79 mounting plate 80 bolt 81 nut 82 lock washer 83 flatwasher 84 plate 85 opening 86 actuator 87 vertical plate/skeg/weldment88 prop drive housing weldment 89 vertical plate/skeg/weldment 90horizontal plate

All measurements disclosed herein are at standard temperature andpressure, at sea level on Earth, unless indicated otherwise. Allmaterials used or intended to be used in a human being arebiocompatible, unless indicated otherwise.

The foregoing embodiments are presented by way of example only; thescope of the present invention is to be limited only by the followingclaims.

The invention claimed is:
 1. A tracked, amphibious vehicle, comprising:a) at least two, spaced, elongated pontoons disposed generally parallelto one another in left and right positions; b) a platform structuresupported by and structurally connecting the pontoons, the platformstructure including a transom, a lowermost generally horizontallyextending panel above a free clearance area under a bottom panel andbetween the pontoons through which terrain and debris can pass; c) ahydraulic drive system that propels the vehicle, said drive systemincluding left and right hydraulic motors mounted on the pontoons, theleft hydraulic motor mounted on the left pontoon, the right hydraulicmotor mounted on the right pontoon; d) at least one series oflongitudinally spaced bogie wheels for supporting said vehicle mountedalong a bottom of each of said pontoons; e) a continuous, endless beltencircling each pontoon and engaging the bogie wheels; f)ground-engaging cleats assembled on an outer surface of each belt andcovering the pontoon bottom for providing traction to the vehicle; g)wherein each of the left and right hydraulic motors interfaces with theendless belts; and h) a supplemental, marine drive assembly thatincludes: a marine drive assembly hydraulic motor having a rotarydevice, shaft, with an axis; a propeller shaft having an axis; whereinthe marine drive assembly hydraulic motor axis and propeller shaft axisare aligned; a universal joint that connects the marine drive assemblyhydraulic motor to the platform structure; wherein the universal jointincludes an attachment that is on the platform structure; a housingincluding a sleeve that contains the propeller shaft, a first plateconnected to the sleeve and a second plate connected to the sleeve belowthe first plate.
 2. The vehicle of claim 1 wherein said first and secondplates define a plane.
 3. The vehicle of claim 1 wherein the propelleris movable between a lower position below said horizontally extendingpanel and an upper position above said horizontally extending panel. 4.The vehicle of claim 1 wherein said sleeve is movable between a lowerposition below said horizontally extending panel and an upper positionabove said horizontally extending panel.
 5. The vehicle of claim 1further comprising a horizontal plate attached to said first plate. 6.The vehicle of claim 5 further comprising a cavitation plate attached tothe first plate and the horizontal plate.
 7. The vehicle of claim 6further comprising an arm connected to the housing at the horizontalplate.
 8. The vehicle of claim 7 wherein the arm attaches to thehorizontal plate at a first position and to the housing at a secondposition that is behind the first position.
 9. The vehicle of claim 1further comprising an actuator that lifts and lowers the propeller andsleeve.
 10. The vehicle of claim 1 further comprising an actuator thatpivots the sleeve and propeller between port and starboard positions.11. A tracked, amphibious vehicle, comprising: a) at least two, spaced,elongated pontoons disposed generally parallel to one another in leftand right positions; b) a platform structure supported by andstructurally connecting the pontoons, the platform structure including atransom, a lowermost generally horizontally extending panel above a freeclearance area under a bottom panel and between the pontoons throughwhich terrain and debris can pass; c) a hydraulic drive system thatpropels the vehicle, said drive system including left and righthydraulic motors mounted on the pontoons, the left hydraulic motormounted on the left pontoon, the right hydraulic motor mounted on theright pontoon; d) at least one series of longitudinally spaced bogiewheels for supporting said vehicle mounted along a bottom of each ofsaid pontoons; e) a continuous, endless belt encircling each pontoondriven by the hydraulic drive system and engaging the bogie wheels; f)ground-engaging cleats assembled on an outer surface of each belt andcovering the pontoon bottom for providing traction to the vehicle; g)wherein each of the left and right hydraulic motors interfaces with theendless belts; and h) a supplemental, marine drive assembly thatincludes: a marine drive assembly hydraulic motor having a rotarydevice, shaft, with an axis; a propeller shaft having an axis; whereinthe marine drive assembly hydraulic motor axis and propeller shaft axisare aligned; a universal joint that connects the marine drive assemblyhydraulic motor to the platform structure; wherein the universal jointincludes an attachment that is on the platform structure; a housingincluding a sleeve that contains the propeller shaft, a first plateconnected to the sleeve and a second plate connected to the sleeve belowthe first plate.
 12. The vehicle of claim 11 wherein said first andsecond plates define a plane.
 13. The vehicle of claim 11 wherein thepropeller is movable between a lower position and an upper positionabove said lower position.
 14. The vehicle of claim 11 wherein saidsleeve is movable between a lower position below said horizontallyextending panel and an upper position above said horizontally extendingpanel.
 15. The vehicle of claim 11 further comprising a horizontal plateattached to said first plate.
 16. The vehicle of claim 15 furthercomprising a cavitation plate attached to the first plate and thehorizontal plate.
 17. The vehicle of claim 16 further comprising an armconnected to the housing at the horizontal plate.
 18. The vehicle ofclaim 17 wherein the arm attaches to the horizontal plate at a firstposition and to the housing at a second position that is behind thefirst position.
 19. The vehicle of claim 11 further comprising anactuator that lifts and lowers the propeller and sleeve.
 20. The vehicleof claim 11 further comprising an actuator that pivots the sleeve andpropeller between port and starboard positions.
 21. A tracked,amphibious vehicle, comprising: a) at least two, spaced, elongatedpontoons disposed generally parallel to one another in left and rightpositions; b) a platform structure supported by and structurallyconnecting the pontoons, the platform structure including a transom, alowermost generally horizontally extending panel above a free clearancearea under a bottom panel and between the pontoons through which terrainand debris can pass; c) a hydraulic drive system that propels thevehicle, said drive system including left and right hydraulic motorsmounted on the pontoons, the left hydraulic motor mounted on the leftpontoon, the right hydraulic motor mounted on the right pontoon; d) atleast one series of longitudinally spaced bogie wheels for supportingsaid vehicle mounted along a bottom of each of said pontoons; e) acontinuous, endless belt encircling each pontoon and engaging the bogiewheels; f) ground-engaging cleats assembled on an outer surface of eachbelt and covering the pontoon bottom for providing traction to thevehicle; g) wherein each of the left and right hydraulic motorsinterfaces with a said endless belt; and h) a supplemental, marine driveassembly that includes: a marine drive assembly hydraulic motor having arotary device, shaft, with an axis; a propeller shaft having an axis;wherein the marine drive assembly hydraulic motor axis and propellershaft axis are aligned; a joint that connects the marine drive assemblyhydraulic motor to the platform structure; wherein the joint includes anattachment that is on the platform structure; a first actuator connectedat a first end portion to the platform and at a second end portionconnected to the supplemental, marine drive system, wherein said firstactuator is positioned to lift and lower the propeller shaft; a secondactuator having a first end portion connected to the platform and asecond end portion connected to the supplemental drive system, whereinsaid second actuator is positioned to steer said propeller shaft betweenport and starboard positions.
 22. The vehicle of claim 21 wherein thepropeller is movable between a lower position below said horizontallyextending panel and an upper position above said horizontally extendingpanel.
 23. The vehicle of claim 21 wherein the first actuator is ahydraulic cylinder.
 24. The vehicle of claim 21 wherein the secondactuator is a hydraulic cylinder.
 25. The vehicle of claim 21 furthercomprising controls on the platform that enable a user to remotely lift,lower or steer the propeller shaft.